function Level() {
  THREE.Scene.call(this)

  this.rotationAutoUpdate = false
  this.matrixAutoUpdate = false

  this.world = new CANNON.World()
  this.world.broadphase = new CANNON.NaiveBroadphase()
  this.world.gravity.set(0, -10, 0)
  this.world.solver.tolerance = 0.05
}

Level.prototype = Object.create(THREE.Scene.prototype)
Level.prototype.update = update

function update() {
  this.world.step(1/60)

  for (var i = 0; i < this.children.length; i++) {
    this.children[i].update()
  }
}
